Blade drive device

ABSTRACT

Because a thin blade is disposed in a space that has a thickness in the optical axial direction, which contains a coil and a magnet, when the blade is driven the blade tends to become unstable, making smooth operation of the thin blade difficult. A blade driving device has a driving member; a frame that is provided with a driving frame chamber that contains the driving member; a blade supporting unit that has an opening and that structures a blade chamber that is separate from the driving frame chamber; and a blade member that is contained in the blade chamber, and that is moved by the driving member to advance into the opening.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International ApplicationPCT/JP2017/019646 filed May 26, 2017, which published as WO 2018/025472on Feb. 8, 2018. The International Application claims priority toJapanese Application No. 2016-151342 filed Aug. 1, 2016. All of theabove applications are incorporated herein by reference in theirentirety.

FIELD OF TECHNOLOGY

The present invention relates to a blade driving device for driving ablade.

BACKGROUND

Blade driving devices are used to change the state of an opening bydriving one or more blade members that advance into the opening, and areused in a variety up optical units, such as camera units, for irises,shutters, iris-shutters, filters, and the like. As conventional bladedriving devices those of the electromagnetically-driven type, that usemagnets and coils as driving sources, are well known (see, JapaneseUnexamined Patent Application Publication 2001-281724).

SUMMARY

In the conventional blade driving device, described above, the blade andthe driving source, such as a coil, are disposed on a base plate thathas an opening, where the coil or the magnet as the driving source isdisposed within a space that is shared with the blade, without apartition.

With such a conventional blade driving device, because a thin blade isdisposed in a space that has thickness, in the axial direction, thatcontains a coil and/or a magnetic, when the blade is driven the bladetends to become unstable, and thus there is a problem in that this makessmooth operation of the thin blade difficult. Moreover, because there isa tendency for dust that is produced through the action of the drivingsource to adhere thereto, there is a problem in that the durability ofthe blade that moves is not adequately high.

In the present invention, the handling of such problems is the problemto be solved. That is, the object of the present invention is to providea structure wherein the blade is not affected by the action of thedriving source, and that not only causes the action of the blade to besmooth, but also improves the durability of the blade.

In order to solve such a problem, the lens driving device according tothe present invention is provided with the following structures:

A blade driving device having a driving member; a frame that is providedwith a driving frame chamber that contains the driving member; a bladesupporting unit that has an opening and that structures a blade chamberthat is separate from the driving frame chamber; and a blade member thatis contained in the blade chamber, and that is moved by the drivingmember to advance into the opening.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is an exploded perspective diagram depicting a blade drivingdevice according to an embodiment according to the present invention.

FIG. 2(a) is an explanatory diagram depicting the movement of the blademember showing the fully opened state.

FIG. 2(b) is an explanatory diagram depicting the movement of the blademember showing the closed state.

FIG. 3 is an external view (plan view) of a blade driving deviceaccording to an embodiment according to the present invention.

FIG. 4 is a perspective diagram of the A-A cross-section in FIG. 3.

FIG. 5(a) is an explanatory diagram depicting the state wherein theblade driving device is assembled onto the lens frame showing a frontview.

FIG. 5(b) is an explanatory diagram depicting the state wherein theblade driving device is assembled onto the lens frame in a plan view).

FIG. 6 is a cross-sectional view along the section B-B in FIG. 5(b).

FIG. 7 is an exploded perspective diagram depicting another structuralexample of the blade driving device.

FIG. 8 is a plan view depicting another structural example of the bladedriving device.

FIG. 9 is an exploded perspective diagram depicting another structuralexample of the blade driving device.

FIG. 10 is an explanatory diagram depicting a camera equipped with theblade driving device.

FIG. 11 is an explanatory diagram depicting a mobile electronic deviceequipped with the blade driving device (camera).

DETAILED DESCRIPTION

A blade driving device according to an embodiment according to thepresent invention is equipped with the structure described above, wherea driving frame chamber that contains the driving member and a bladechamber that contains the blade member are separated spatially. Throughthis, the blade supporting unit that structures the blade chamber issupported so as to enable smooth movement of a blade member that is in athin shape. Moreover, because the blade member is contained within ablade chamber that is separate from the driving frame chamber, the dustfrom the action of the driving member is blocked, enabling an increasein durability of the blade member.

Embodiments according to the present invention will be explained belowin reference to the drawings. In the descriptions below, identicalreference symbols in the different drawings below indicate positionswith identical functions, and redundant explanations in the variousdrawings are omitted as appropriate. In the figure, the arrow in the Zdirection indicates the optical axial direction (the thickness directionof the blade driving device; the arrow X indicates the direction ofmovement of the blade member; and the direction of the arrow Y indicatesa direction that is perpendicular to the X and Z directions.

As illustrated in FIG. 1, a blade driving device 1 in an embodimentaccording to the present invention comprises a driving member 2, a frame3, a blade supporting unit 4, and blade members 5 (5X and 5Y). The frame3 is structured from a base frame 10 and a cover frame 11 that coversthe base frame 10, to form a driving frame chamber 3S that contains thedriving member 2 therein. The driving member 2 is supported movably on asupporting face 10A of the base frame 10, so as to move the blademembers 5 (5X and 5Y) through moving on a plane.

A magnet 20 and a coil 21, which are the driving source, are attached tothe driving member 2 and the frame 3. In the example in FIG. 1, themagnet 20 is attached to the driving member 2 and the coil 21 isattached to the frame 3 (the cover frame 11), where power is applied tothe coil 21 through a wiring board (a flexible substrate) 22, to causethe driving member 2 to undergo reciprocating motion in the X directionin the figure. The driving member 2 is supported movably in a supportinggroove 10B of a supporting face 10A on a bearing 23. Moreover, a Hallelement (detecting member) 30, for detecting movement of the drivingmember 2 or the blade member 5 (5X, 5Y) is disposed on the wiring board22 at a position corresponding to the magnet 20. Note that the drivingsource is disposed horizontally, or essentially horizontally, inrelation to the direction in which a protruding part 4P, describedbelow, is inserted into a slit 6S (hereinafter termed the “insertiondirection”).

The blade members 5 (5X, 5Y) are connected to the driving member 2,either directly or through connecting members 7. In the example depictedin FIG. 1, the connecting member 7 is borne within the frame 3. In theconnecting member 7, a bearing portion 7A, in the center, is borne on ashaft 10P of the base frame 10, where connecting portions 7B, on bothends thereof, pass through elongated holes 4B of the blade supportingunit 4, and are respectively connected in connecting holes 5B of theblade members 5X and 5Y, where, near the center, the connecting portion7C passes through an elongated hole 4C of the blade supporting unit 4,and is connected to the driving member 2. Through this, when the drivingmember 2 undergoes reciprocating motion linearly along the X direction,the connecting member 7 rotates around the shaft 10P, so that the blademembers 5X and 5Y, which are connected to the connecting portions 7B,move in mutually opposing directions along the X direction.

The blade member 5 (5X, 5Y) is supported on a blade supporting unit 4.The blade supporting unit 4 is structured from a pair of supportingplates 12 and 13, made from thin metal plates, or the like. The pair ofblade supporting plates 12 and 13, which are thin members, hold theblade member 5 (5X, 5Y) therebetween, and stepped portions 4T, at theperiphery edges thereof, are attached together, to form a blade chamber4S that contains the blade member 5 (5X, 5Y) in the interior thereof.The blade supporting unit 4 has an opening 4A around the optical axis,along the thickness direction (the Z direction in the drawings) of theframe 3. The blade member 5 (5X, 5Y) is moved, by the driving member 2,to advance into the opening 4A. In the example in the figure, the blademember 5 (5X, 5Y) has an opening 5A, where the degree of overlap of theopening 5A in the opening 4A is adjusted variably by the movement in theX direction in the figure.

Explaining, in greater detail, the example in the figure, a protrusion10Q of the base frame 10 fits into a hole 4Q of the blade supportingunit 4, to engage the blade supporting unit 4 with the base frame 10,and, additionally, the protrusion 10Q is inserted into a guide hole(elongated hole) 5Q of the blade member 5 (5X, 5Y) that is supported onthe blade supporting unit 4, to guide the movement of the blade member 5(5X, 5Y). Moreover, within the frame 3 (the base frame 10), a magneticmaterial 24 is disposed to hold the blade member 5 in an initialposition, and to attract the driving (frame) member 2 in the opticalaxial direction relative to the base frame 10.

FIG. 2 depicts the movement of the blade member 5 (5X, 5Y). In theexample in the figure, an example is shown wherein the blade drivingdevice 1 has the function of an iris device for variably adjusting thebrightness of light that passes through the opening 4A. (a) depicts thefully open state of the opening 4A through the rotation of theconnecting member 7 by the movement of the driving member 2 (not shown),described above, and (b) depicts the state wherein the opening area isclosed through overlapping of the opening 5A within the opening 4A.While, in the example in the figure, an example of an iris device isdepicted, the blade driving device 1 may instead function as a shutterdevice for blocking the light that passes through the opening 4A byfully closing the opening 4A by the blade members 5 (5X and 5Y)overlapping, or may function as a filter device through attaching afilter, for limiting the wavelengths or brightness of the light, to endportions of the openings 5A of the blade members 5 (5X and 5Y).

Note that in the example depicted in FIG. 2, in the connecting portionbetween the driving member 2, not shown, and the connecting member 7,one end is secured to the driving member 2, and the other end isprovided with an elastic member (a leaf spring) 14 that presses theconnecting portion 7C of the connecting member 7. Through connecting thedriving member 2 and the connecting member 7 through the elastic member14 in this way, the movement of the driving member 2 can be transmittedto the connecting member 7 without rattling, making it possible toincrease the accuracy of movement of the blade members 5 (5X and 5Y),enabling an increase in the accuracy of brightness adjustment.

FIG. 3 depicts an external view of the blade driving device 1, and FIG.4 depicts a perspective diagram along the cross-section A-A in FIG. 3.In the blade driving device 1, the frame 3 structures a driving framechamber 3S that contains the driving member 2, and the blade supportingunit 4 structures a blade chamber 4S that is separate from the drivingframe chamber 3S. Moreover, the blade supporting unit 4, which containsthe blade member 5, protrudes to the outside along the direction ofmovement of the driving member 2 (the X direction in the figure) frompart of the thickness of the frame 3, between the base frame 10 and thecover frame 11, and the opening 4A of the blade supporting unit 4 islocated outside of the frame 3. The blade supporting unit 4 is a memberof a thin shape, structured so as to be thinner than the thickness ofthe frame 3.

The outer peripheral edge of the frame 3 has a recessed portion 3A atthe position wherein the blade supporting unit 4 protrudes. Throughthis, the protruding part 4P and opening 4A of the blade supporting unit4 are located within a space that is outside of the frame 3, because ofthe recessed portion 3A. Moreover, a stepped portion 3B for supportingthe content, by the frame 3, is provided in the recessed portion 3A ofthe frame 3. Given this, a gap S is formed between the protruding part4P of the blade supporting unit 4 that protrudes in the recessed portion3A, and the outer periphery of the recessed portion 3A of the frame 3.

Given the blade driving device 1, described above, first the bladesupporting unit 4 that structures the blade chamber 4S can support thethin blade member 5 so as to enable smooth movement thereof. Moreover,because the blade member 5 is contained within the blade chamber 4S,which is separate from the driving frame chamber 3S, the dust due to theaction of the driving member 2 is blocked, enabling the durability ofthe blade member 5 to be increased.

Moreover, the thin blade supporting unit 4 protrudes the outside, from aportion of the frame 3, in the thickness direction thereof, and anopening 4A is provided in this protruding part 4P, and thus theprotruding part 4P enables the opening 4A to be disposed on the opticalaxis of the optical components, through insertion of the protruding part4P from the outside in respect to the optical components, such as thelens frame. Through this, this can prevent the optical components andthe blade driving device 1 from being disposed stacked in the opticalaxial direction, enabling the combination of the optical components andthe blade driving device 1 to be structured more thinly.

Moreover, a gap S is provided between the protruding part 4P of theblade supporting unit 4 and the outer periphery of the recessed portion3A of the frame 3, and the protruding part 4P protrudes in acantilevered state, thus enabling insertion of the protruding part 4Pfrom the outside of a portion of the integrated optical components,enabling the opening 4A to be disposed on the optical axis of theoptical components. This makes it possible to install the blade drivingdevice 1 into the assembled optical components after completion ofadjustments, and the like, of the optical components, enabling asimplification in the adjustments of the optical components that are tobe assembled together with the blade driving device 1. Note that,conversely, the adjustments to the optical components may be carried outafter assembly together with the blade driving device 1.

Note that while the example in the figure depicted in an example whereinthe driving member 2 is a VCM (Voice Coil Motor) as a driving mechanismfor causing reciprocating motion on a plane, the driving method is notlimited particularly thereto, but rather any of a variety of drivingmethods may be used.

FIG. 5 and FIG. 6 depicts the state wherein the blade driving device 1is assembled together with a lens frame 6. The lens frame 6 is providedwith a slit 6S on a side face, where the protruding part 4P of the bladesupporting unit 4 is inserted into the slit 6S of the lens frame 6,contained within the recessed portion 3A of the frame 3. The lens frame6 supports, as a single unit, lenses L1, L2, and L3 that are disposed tothe front and the rear of the blade supporting unit 4. Here theprotruding part 4P of the blade supporting unit 4 is inserted into aspace between the lens L2 and the lens L3, where the lenses L1 and L2are disposed to the front side (the object side as parent of the bladesupporting unit 4, and the lens L3 is disposed to the rear side (theimaging element side) of the blade supporting unit 4. A stepped portion6A is provided on a side frame in the lens frame 6, where the steppedportion 6A rests on the stepped portion 3B of the frame 3, to assemblethe blade driving device 1 with good seating in relation to the lensframe 6. However, in another embodiment, the stepped portion 3B and thestepped portion 6A need not necessarily be provided. In such a case,assembly to the frame 3 is possible regardless of the front/backorientation of the lens frame 6.

Such a structural example enables the lens frame 6, which supports thelenses L1, L2, and L3, integrally, to have the adjustments betweenlenses, and the like, be carried out with the lens frame 6independently, and the blade supporting unit 4 is inserted into the slit6S, to assemble the blade driving device 1 together with the lens frame6, after these adjustments. Moreover, the blade supporting unit 4 isinserted onto the optical axis of the lens frame 6 from the side of thelens frame 6, enabling the assembly to be thin in the optical axialdirection, rather than the lens frame 6 and the blade driving device 1being stacked in the optical axial direction. At this time, because theoptical axial direction thickness of the frame 3 is thin when comparedto the optical axial direction of thickness of the lens frame 6, theblade driving device 1 can be assembled together within the thickness ofthe lens frame 6, enabling assembly with good spatial efficiency alongthe optical axial direction. Note that, although omitted from thedrawings, the slit 6S is formed passing all the way through the interiorof the lens frame 6. Because of this, at the time of assembly, theprotruding part 4P may be inserted from either side of the lens frame 6(slit 6S). However, in another embodiment, the slit 6S need not pass allthe way through.

FIG. 7 and FIG. 8 depicts another structural example of a blade drivingdevice 1. In the blade driving device 1 depicted in FIG. 1, the magnet20 and the coil 21 that are the driving source were provided extendingalong the direction of protrusion of the blade supporting unit 4 withinthe frame 3 (the X direction in the figure). In contrast, in the exampledepicted in FIG. 7, the magnet 20 and the coil 21 that are the drivingsource extend along the direction that is perpendicular (the Y directionin the figure) relative to the direction of protrusion of the bladesupporting unit 4 within the frame 3 (the X direction in the figure). Inthe example in FIG. 7 as well, the driving member 2 moves in the Xdirection in the figures, so driving is the same as in the exampledepicted in FIG. 1.

For the direction in which the driving source extends, this directionmay be selected as appropriate in order to provide the desired drivingforce in the direction of movement of the driving member 2 (the Xdirection in the figures). For example, the example in FIG. 1 and theexample in FIG. 7 may be combined with the driving source (the magnet 20and the coil 21) provided extending along the direction of protrusion ofthe blade supporting unit 4 in the frame 3 (the X direction in thefigures), and provided extending in the direction that is perpendicularto the direction in which the blade supporting unit 4 protrudes (the Xdirection in the figures). For example, a portion of the driving sourcemay be provided extending along the direction of protrusion of the bladesupporting unit 4 (the X direction in the figures), and provided in adirection that is perpendicular to the direction of protrusion (the Xdirection in the figure), with the driving source in a L shape.

Note that the driving source is disposed perpendicularly, or essentiallyperpendicularly, in relation to the direction of insertion. Moreover, inanother embodiment, the example in FIG. 1 and the example in FIG. 7 maybe combined, provided with both a driving source that is provided alongthe direction of protrusion of the blade supporting unit 4 (the Xdirection in the figures) and a driving source that is provided in adirection that is perpendicular to the direction of protrusion of theblade supporting unit 4 (the X direction in the figures).

Moreover, in the example depicted in FIG. 7 and FIG. 8, the frame 3 isprovided with an attaching protrusion 3P. This makes it possible toassemble the blade driving device 1 easily to a side face, or the like,of the lens frame through the provision of a fitting hole, in the sideface of the lens frame, or the like, into which the attaching protrusion3P is inserted.

FIG. 9 depicts another structural example of a blade driving device 1.In this example, in the blade member 5, a plurality of blade members 5Xand 5Y are provided overlapping, where one of the blade members 5X issecured directly to the driving member 2 and the other blade member 5Yis connected through a connecting member 7 to the driving member 2.Specifically, the securing portion 2A of the driving member 2 is secureddirectly to a secured portion 5C of the blade member 5X through a hole4Q1 of the blade supporting unit 4. Moreover, the driving member 2 isconnected to a connecting portion 7C of the connecting member 7. Whenthe driving member 2 moves in the X direction in the figures, the blademember 5X moves integrally therewith, and, the connecting member 7 isrotated around the shaft 10P. The blade member 5Y that is connectedthrough the connecting hole 5B to the connecting portion 7B at the endportion of the connecting member 7 moves in the opposite direction fromthat of the blade member 5X.

In the example depicted in FIG. 9, the one blade member 5X movesintegrally with the driving member 2, and thus in the mechanism whereinthe pair of blade members 5X and 5Y are moved in mutually opposingdirections by a single driving member 2, there will be less of arattling effect than there would be in a case wherein both of the blademembers 5X and 5Y were connected through connecting members 7, enablingan improvement in the movement accuracy of the blade members 5X and 5Y.Through this, this enables, for example, a brightness adjustment withbetter accuracy. Note that the driving member 2 may be divided into leftand right sides, and the blade member 5X and the blade member 5Y may besecured directly to the respective driving members 2. In this case, theconnecting member 7 would be unnecessary, enabling a brightnessadjustment with even higher accuracy.

FIG. 10 depicts a camera 100 as an optical unit that is provided withthe blade driving device 1. The blade driving device 1 may be assembledtogether with the lens frame 6 as described above, and may be mounted ina case 100A wherein an imaging element 101 is mounted, to structure acamera 100. Moreover, various types of optical units can be producedthrough assembling the blade driving device 1 together with otheroptical components. Such a camera 100 or optical unit can be madethinner, enabling a reduction in the thickness of the space forinstallation along the optical axial direction. Moreover, because theblade driving device 1 can be assembled and integrated after theadjustments to the lens frame 6, and the like, have been completed, thisenables simple and highly accurate adjustments, and enables simplemounting through integration of the blade driving device 1.

FIG. 11 depicts a mobile electronic device (mobile information terminal)200 that is equipped with the camera 100 described above. The mobileelectronic device 200, such as a smart phone, or the like, has severelimitations on the thickness of the units packaged in the interiorthereof, but the camera 100, as described above, enables a reduction inthickness through assembly with the blade driving device 1 containedwithin the thickness of the lens frame 6, thus enabling packaging withexcellent spatial efficiency in a mobile electronic device 200 thattargets high portability and design characteristics. Note that themembers disposed within the frame 3 in these examples have the layoutpositions and shapes designed so as to be assembled sequentially fromone side of the base frame 10.

While embodiments according to the present invention were described indetail above, referencing the drawings, the specific structures thereofare not limited to these embodiments, but rather design variationswithin a range that does not deviate from the spirit and intent of thepresent invention are also included in the present invention. Inparticular, while in the embodiments set forth above, the frame 3 of theblade driving device 1 was structured from a member that was separatefrom the blade supporting unit 4, instead the frame 3 may be structuredintegrally with the blade supporting unit 4, and the driving framechamber 3S within the frame 3 and the blade chamber 4S within the bladesupporting unit 4 may be separated through a partition. Moreover,insofar as there are no particular contradictions or problems inpurposes or structures, or the like, the technologies of the variousembodiments described above may be used together in combination.

The invention claimed is:
 1. A blade driving device, comprising: adriving member; a frame equipped with a driving frame chamber thatcontains the driving member; a blade supporting member that has anopening, and that structures a blade chamber that is separate from thedriving frame chamber; and a blade member that is contained in the bladechamber and that is moved by the driving member to advance into theopening, wherein the blade supporting member is disposed with a portionthereof protruding to the outside of the frame, with the opening outsideof the frame, wherein in the frame, a recessed portion is formed in anouter peripheral edge, and the blade supporting member protrudes intothe recessed portion, wherein a lens frame that has a slit into whichthe blade supporting member is inserted is contained in the recessedportion, wherein the frame includes a first subframe and a secondsubframe, the first subframe defines a first recess on a first planeperpendicular to the optical axis, the second subframe defines a secondrecess on a second plane perpendicular to the optical axis, the firstrecess and the second recess together form the recessed portion, whereinthe blade supporting member includes a protruding member that extends ina direction parallel to the first plane and the second plane, theprotruding member overlaps at least in part with the recessed portion,and the blade supporting member is sandwiched between the two subframes,and wherein the opening is formed in the protruding member.
 2. The bladedriving device as set forth in claim 1, wherein: a stepped portion,wherein the lens frame is supported by the frame, is provided in therecessed portion.
 3. The blade driving device as set forth in claim 1,wherein: the lens frame supports integrally lenses that are disposed tothe front and to the rear of the blade supporting member.
 4. The bladedriving device as set forth in claim 1, further comprising: a magnet isdisposed in the frame or the driving member, and a coil is disposed inthe other, wherein the driving member moves on a plane.
 5. The bladedriving device as set forth in claim 1, further comprising: a connectingmember connecting the driving member and the blade member is providedwithin the frame.
 6. The blade driving device as set forth in claim 5,wherein: the connecting member is supported through an elastic memberpreventing rattling.
 7. The blade driving device as set forth in claim1, wherein: in the blade member, a plurality of members are providedoverlapping, where at least one of the blade members is secured directlyto the driving member.
 8. The blade driving device as set forth in claim1, wherein: the blade supporting member is provided with a steppedportion structuring the blade chamber.
 9. The blade driving device asset forth in claim 1, wherein: the blade member blocks light that passesthrough the opening.
 10. The blade driving device as set forth in claim1, wherein: the blade member adjusts variably brightness of light thatpasses through the opening.
 11. The blade driving device as set forth inclaim 1, wherein: the blade member limits a wavelength or brightness oflight that passes through the opening.
 12. The blade driving device asset forth in claim 1 further comprising: a detecting member detectingmovement of the driving member or the blade member.
 13. An optical unitprovided with a blade driving device as set forth in claim
 1. 14. Acamera provided with a blade driving device as set forth in claim
 1. 15.A mobile electronic device provided with a blade driving device as setclaim
 1. 16. The blade driving device as set forth in claim 1, whereinthe direction in which the outer peripheral edge of the frame isrecessed and the direction in which the blade supporting memberprotrudes are perpendicular to the optical axis.